1. Field of the Invention
This invention relates to vehicle brake lights and, more particularly, to vehicle brake lights having a plurality of lights with the lights illuminating in response to the degree of brake application pressure.
2. Description of the Prior Art
U.S. Pat. No. 4,682,146 (Friedman) discloses an indicator light system using a horizontally disposed tube filled with a rare gas. The gas tube is connected to turn signal indicators and the light in the tube propagates from either the left hand side of the tube or the right hand side of the tube, depending on the direction of travel of the vehicle. For a left hand turn, the light propagates from the right hand side progressively to the left hand side, indicating a left turn. For a right turn, the opposite happens. That is, the light propagates from the left side progressively to the right side. The apparatus is not degree-based responsive.
U.S. Pat. No. 5,606,310 (Egger et al) discloses a safety system in which a pair of lights illuminate when hard braking pressure is applied. A pressure transducer is used to sense the pressure of the brake pedal application. The system is coupled to the ordinary brake light system to provide different light effects depending on brake pressure applied. However, the light effects could be mistaken as a hazard warning light function.
U.S. Pat. No. 5,610,578 (Gilmore) discloses a light system indicative of pressure application on the brake system. Deceleration is sensed as well as brake pressure application. The brake illumination system provides brake light intensity as a function of the deceleration of the vehicle. The motion of the brake arm during braking is used as a determining element. This apparatus, like the '310 (Egger) apparatus, utilizes the brake lights in an ordinary brake light system circuit. No additional lights or light elements are used. The apparatus is dependent on ambient conditions and bulb life to indicate intensity. Its is unclear how light intensity is translated into vehicle deceleration.
U.S. Pat. No. 5,682,137 (Li) discloses a safety system for vehicles which indicates acceleration and deceleration of the vehicle. The system utilizes inertial forces to determine acceleration and deceleration and sequentially activates lights in response to acceleration and deceleration. Red lights are used in response to deceleration, and green lights are used in response to acceleration. It will be noted that a problem with this system is that changes in the attitude of the vehicle will also cause changes of the sensitivity of the apparatus. That is, going uphill or going downhill which changes the attitude of the vehicle, will result false indications of acceleration or deceleration. The apparatus is also sensitive to vehicle loading changes which affect the attitude of the vehicle.
U.S. Pat. No. 5,831,523 (Lange) discloses a vehicle light system which uses a plurality of spaced apart light emitting diodes disposed about the rear window. Both red and yellow L.E.D.s are used with yellow L.E.D.s used as an adjunct to the directional indicators and red L.E.D.s tied into the brake system. The red L.E.D.s are activated when the brake light system is activated. The lights actuate sequentially, not in response to brake pressure. The red lights actuate sequentially as an indication that the brakes have been actuated, but they are not indicative of brake pressure. That is, the apparatus is independent of brake application intensity. The red L.E.D.s illuminate sequentially from the top center of the rear window outwardly and downwardly on the sides of the window.
The apparatus of the present invention utilizes red L.E.D.s or high intensity lamps or the like which illuminate sequentially in response to intensity of brake application pressure. That is, a ladder-effect of the red L.E.D.s occurs in direct response to brake pressure. Two embodiments are included, the first being an original equipment type installation and the second being an after market installation.